Boiling water: With a camp stove, bring the water to a full rolling boil for one minute, then allow it to cool before drinking. This is more of an option for multi-day tramping water purification, however, most trampers or hunters avoid this method as it’s time consuming and requires you to carry extra fuel.
Iodine tablets: Iodine tablets are easy to use, inexpensive, and can be purchased at most outdoor stores or online. They do, however, leave a strange aftertaste that some people find unpleasant, and they take 30-minutes to render water safe to drink.
Water filters: There’s hundreds of backcountry water filtration systems on the market. Ultimately, the type and length of activity, anticipated water sources, and number of people you are filtering for should determine what system you go with.
Drinking straight from rivers or streams should be a last resort. When there is an immediate risk of severe dehydration, drinking from rivers can save you, as the risk of an infection isn’t going to hit you for a week or two, with the majority of possible infections typically treated with antibiotics. When drinking directly from rivers or streams, never drink water that is stagnant and not flowing—always try to find a fast-moving section where the bacteria is less likely to be congregating in large numbers.
Even if you don’t go the route of iodine tablets, a lot of experienced trampers or hunters will carry them with, even on day trips, to use if they get stuck overnight or if the backcountry water purification systems they are carrying fails. A few paper coffee filters will come in handy to filter out small particles when using purification tablets. Lastly, even using an expensive filter can leave water gathered at a backcountry source tasting a bit “lake-y.” Electrolyte powder or tablets are a great way to cover this up, and supplementing electrolytes is something you should be considering as a part of your hydration plan anyway.